/*
   Copyright (c) 2011, 2012 Mizar Tools Contributors (mizartools.org)

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/
/*  Contributors :
 *	2011-02-18 Marco Riccardi - initial implementation
 *  2012-04-06 Marco Riccardi - added message in DliParseException
 *
 */
package org.mizartools.dli;

public class Num extends Term {

	private int nr = -1;

	public static Num newInstance(String string) throws DliParseException {
		Num num = new Num();
		int position = string.indexOf(" ");
		if (position == -1) {
			throw new DliParseException("["+string+"] is not valid in Num");
		}
		if (!string.substring(0, position).equals("$N")){
			throw new DliParseException("["+string+"] is not valid in Num");
		}
		try{
			num.nr = Integer.valueOf(string.substring(position+1, string.length()));
		}
		catch (Exception e){
			throw new DliParseException("["+string+"] is not valid in Num");
		}
		return num;
	}
	
	private Num(){}
	
	public Num(int nr) throws DliException {
		if (nr < 1)	throw new DliException();
		this.nr = nr;
	}
	
	@Override
	public String toString() {
		return "$N "+nr;
	}
	
}
